The field of the invention relates generally to circuit protection devices, and more specifically to transient voltage surge suppression devices.
Transient voltage surge suppression devices, sometimes referred to as surge protection devices, have been developed in response to the need to protect an ever-expanding number of electronic devices upon which today's technological society depends from high voltages of a short, or transient duration. Electrical transient voltages can be created by, for example, electrostatic discharge or transients propagated by human contact with electronic devices themselves, or via certain conditions in line side electrical circuitry powering the electronic devices. Thus, it is not uncommon for electronic devices to include internal transient voltage surge suppression devices designed to protect the device from certain overvoltage conditions or surges, and also for line side circuitry powering the electronic devices in an electrical power distribution system to include transient voltage surge suppression devices. Examples of electrical equipment which typically employ transient voltage protection equipment include telecommunications systems, computer systems and control systems.
Transient voltage surge suppression devices for electrical power systems are commonly employed to protect designated circuitry, which may include expensive pieces of electrical equipment, critical loads, or associated electronic devices powered by the system. The surge suppression devices normally exhibit a high impedance, but when an over-voltage event occurs, the devices switch to a low impendence state so as to shunt or divert over-voltage-induced current to electrical ground. Damaging currents are therefore diverted from flowing to associated load side circuitry, thereby protecting the corresponding equipment, loads and electronic devices from damage. Improvements, however, are desired.